1999-05-29 04:00:00 PDT Montreal -- Dusty Baker faced one of those no-win decisions that earn managers those hefty six-figure salaries. In a 2-2 game on the road, should he turn to his exhausted bullpen for the eighth inning or let his stud starter go out there again even though he's thrown 120 pitches through seven?

Damned if you do, damned if you don't, and damned if the Giants aren't back in second place after Baker's decision backfired last night.

The much-improved Montreal Expos scored twice off Russ Ortiz in the bottom of the eighth to beat the Giants 4-2 at Olympic Stadium, where 6,535 fans made as much noise as they could by banging seats inside this mausoleum.

Arizona beat New York 2-1 last night, sending the Giants to second place for just the second time this season.

"I thought he was at his best in the seventh and eighth inning as far as locating his pitches," Mayne said. "I had no problem at all sticking with him. If we'd have made a couple of good pitches there he would have gotten out of it."

After he fell to 6-3, his five-game winning streak over, Ortiz said fatigue was no factor at all.

"I had better stuff in the sixth, seventh and eighth innings than I did in the first five," he said. "My location was better and I threw more strikes with my changeup. It was just a matter of two pitches that didn't go where I wanted them to."

Those were a curveball to pinch- hitter Orlando Merced in the seventh, which he knocked out of the park to tie the game 2-2, and a fastball down the pipe to rookie Michael Barrett in the eighth.

Barrett drove the ball into the gap in right-center for a double that scored Jose Vidro, who had singled ahead of Barrett. Baker finally pulled Ortiz and brought in Felix Rodriguez, who allowed a Mike Mordecai single that drove in pinch- runner Manny Martinez for insurance.

One could understand Baker's logic in sticking with Ortiz, who carried the league's best ERA into the game (but lost the lead by night's end to Chicago's Kevin Tapani). But once Vidro singled in the eighth, even Mayne said he looked into the dugout thinking Baker might make a switch, considering Barrett had already doubled and singled against Ortiz and had been 4-for-5 against him for the season.

Baker stuck with his ace, however.

"The fact was we played 12 innings (Thursday) and used the bullpen a lot," he said. "I conferred with Maynard and Russ both. He was actually getting stronger. Russ just got a ball up to Vidro and a ball up to Barrett."

Baker's decision was not the only intrigue last night. The other mystery? What happened to the offense, which was so fat and happy at the start of this trip and is now scratching for runs.

"Some days you feel outstanding and you score as many runs as you want, and the next day you can't score at all," said right fielder Ellis Burks, whose slump reached 4-for- 39 while his average dropped to .241 last night.

"We scored 17 then seven the first two days in St. Louis, then two yesterday and two today," Burks said. "That's baseball. If I could explain everything that happened I could tell you what the hell I was doing wrong."

After Marvin Benard singled to lead off the game and manufactured the first Giants' run with his legs, Aurilia provided the second run an inning later with a homer to dead center, his team-leading ninth in 155 at-bats. That matched the nine he hit all of last season in 413 at-bats.

"It's a product of knowing I was going to play and working hard in the offseason, getting more consistent with my game plan out there and being confident," Aurilia said. "Playing every day has a lot to do with it. Knowing you're going to be in there takes some of the pressure off."

Expos pitcher Javier Vazquez allowed those runs, then closed the spigot for the rest of his seven-inning start. The poor kid went 0-3 against the Giants last year, all of the losses against Kirk Rueter, but this time he stood firm against Ortiz and went home with a positive no-decision.

The Giants have a 2-2 record on a road trip that began like a house afire. They hope to reignite things tonight behind Shawn Estes against a Montreal team that has now won three straight.